The number of Internet users has increased very rapidly due to the scalability of the network. The users demand higher bandwidth and better throughput in the case of on demand video, or video conference or any real time distributed network system. Performance is a great issue in any distributed networks. In this paper we have shown the performance of the multicast groups or clusters in the distributed network system. In this paper we have shown the performance of different users or receivers belongs to the multicast group or cluster in the distributed network, transfer data from the source node with multirate multicast or unirate multicast by considering packet level forwarding procedure in different sessions. In this work we have shown that how the throughput was effected when the number of receiver increases. In this work we have considered the different types of queue such as RED, Fair queue at the junction node for maintaining the end to end packet transmission. In this work we have used various congestion control protocol at the sender nodes. This paper we have shown the performance of the distributed cluster network by multirate multicast.
1. Introduction
The users i.e. the receivers are connected to the source for transferring data or exchanging information. Here the source and the receivers are forming a network, that network is scalable i.e., in the network any new user or receiver can join. According to the real world scenario any number of existing user or receiver can leave from the cluster network can join different cluster or group. Each cluster be from a distributed network and well connected with other network. For any particular multicast group in the distributed network, the consist members of the group run different application program and required different packet size and data rate.
The performance of the distributed network in heterogeneous system, obtained by markovian model [1] and the queuing processing delay at the junction node.
Sending packets to the destination node with the minimum cost transmission delay, multicast session network coding techniques scheme used [2]. The end to end packet transmission in a set of active elastic sessions over a network, the session traffic [3] routed to the destination node through different path. The collision free broadcasting technique used [4] to minimize the latency and the number of transmissions in the broadcast network for end to end packet transmission in the distributed cluster network. The alternative ways for end to end packet forwarding used minimal congestion feed back signals from the router [5] and split the flow between each source destination pair. In end to end packet transmission, the random delay and TCP–congestion control [6] in the network is a issue. Receiver adjusts the rate based on the congestion level in Multicast Network [7] to reduce the congestion. In the real life scenario multicast traffic can cause more packet loss than uncast traffic for example in internet. The resource allocation by the Max –min fairness [8,9] and proportional fairness can reduce the traffic load in the network. The control multicast in the Network by using TCP [10,11] reduce the traffic load in the network. The inverted tree structure implemented in IP based network with the multicast session [12,13] to achieve better performance. The TCP congestion and the effect of that on the throughput of Multicast Group have greater impact in the system network [14]. Since the data packet be transferred between the source and receiver for end to end connection. The path between the source and receiver is not peer to peer, there be at least one junction node in between them .Due to limited bandwidth in the connecting paths, and queuing delay, data packet may be loss. The packet processing delay at the junction node (it is random service time) and the propagation time in the link be consider, the packet transmission delay at the junction node be negligible. The different receivers take data packet from the source node via the junction node (there may be more than one junction nodes in the source to receiver link). Now different receivers taken data packet with different rate in the multicast group of the distributed network in a multicast session. It is called the multirate multicast .If all the receiver node taken data packet with same rate it is called unirate multicast. Each multicast session is the collection of virtual session [15,16].
where 
is the jth multicast session, and n is the number of node ( receiver) clearly, cardinality(
)
n because in a particular session all receiver may not received data packet . 
is the virtual session in the j-th multicast session for the ith receiver node in the multicast group. Different type of tree formed in the cluster of the distributed network like the Figures 1,2,3.
In Figure 1 there is one multicast group and one junction node, In Figure 2 there are two multicast group and two junction node In Figure 3 three multicast group and three junction node. The receiver node takes data packet from the source node via the junction node through the source to receiver link path. The different types of queue like RED, FQ, SFQ attach at the junction node to capture the packet loss and measure the delay for the multicast group in the multirate multicast session. Figure 4 represent the junction node [17].
Figure 4 represents the junction node of the network. The packets approach the junction node randomly and the queue stored the packets. The packets stored into the queue in the order n + 1, n, n – 1… i.e., the 
packet be forwarded to the processing unit after that the 
and 
be forwarded to the processing unit. In side the queue there be waiting time for each packet and each packet have random service time or processing time according to the size of the packet and the destination multicast group. By using the packet level simulation we check how the throughput, delay, packet loss how the throughput be effected by increasing the number of receiver in the multicast group. The paper is structured as follows Section 1 is introduction, Section 2 presents Proposed model Section 3 presents the algorithms for the mathematical models, Section 4 and 5 represents simulation results and the conclusion.